Device for Supplying Oxygen to the Occupants of an Aircraft and Pressure Regulator for Such a Device

ABSTRACT

Device for supplying oxygen to occupants of an aircraft comprising an oxygen source at a first pressure known as a high pressure, a first oxygen supply line at a second pressure known as an intermediate pressure, first means for expanding/regulating the oxygen from the source to the intermediate second pressure, to feed into the first oxygen supply line, a second oxygen supply line at a third pressure known as the low pressure, second means for expanding/regulating the oxygen from the source to the third pressure to feed into the second oxygen supply line, characterized in that the first and second expansion/regulating means are positioned within one and the same regulator.

The present invention relates to a device for supplying oxygen to occupants of an aircraft and a pressure regulator for such a device.

The invention relates in particular to a device for supplying oxygen to occupants of an aircraft, comprising an oxygen source at a first pressure known as a high pressure, a first oxygen supply line at a second pressure known as an intermediate pressure, first means for expanding/regulating the oxygen from the source to the second intermediate pressure, to feed the first oxygen supply line, a second oxygen supply line at a third pressure known as a low pressure, second means for expanding/regulating the oxygen from the source to the third pressure to feed the second oxygen supply line.

The emergency oxygen supply systems employed on board aircraft may comprise a number of high pressure oxygen gas cylinders (typically under a nominal pressure of between 120 and 200 bar). In case of depressurization of the aircraft cabin, the oxygen is delivered to the passengers via distribution lines. The oxygen delivered is regulated using, on the one hand, a first expansion valve placed on the cylinder to convert the high pressure to an intermediate pressure (typically between 5 and 8 bar), and then, on the other, using a pressure regulating valve to convert the intermediate pressure to a low pressure (typically between 0.5 and 5 bar gauge).

Pneumatic pressure regulating valves for converting the intermediate pressure to a low pressure are known. However, these pneumatic valves do not allow an accurate regulation of the oxygen flow rate supplied to the passengers according to the altitude. This causes overconsumption of oxygen.

Electronic regulators are also known. FIG. 3 schematically shows such a pressure regulator comprising a flapper 17 moving in a duct 18 for regulating the pressure of a gas between an upstream part A issuing from a pressurized cylinder and a downstream part B. The position of the moving flapper 1 is controlled by an electronic module 28 according to the real pressure Pr measured in the duct 18 and a pressure setpoint Pc.

Such regulators, which serve to optimize the quantity of oxygen delivered to the passengers, by an accurate regulation of the oxygen flow supplied according to the altitude of the aircraft, are described in particular in documents FR2 858 560 A1 and EP-A-499505.

In general, the abovementioned emergency oxygen circuits also comprise quick installation masks for the aircraft crew. These quick installation masks generally have their own pressure regulator, and must therefore be fed by an oxygen feed line at the intermediate pressure.

Emergency masks for the passengers are of the continuous flow type and do not have pressure regulators. The masks for the passengers must therefore be fed via a low pressure oxygen feed line. The feed line of the passenger masks generally consists of a branch of the feed line for the quick installation masks. This branch comprises pneumatic or electronic pressure regulating means.

The known architectures therefore require having several sections of intermediate pressure oxygen feed lines and a plurality of associated equipment (pressure regulators). Hence these known circuits incur safety risks and have a complex and costly structure.

It is an object of the present invention to overcome all or part of the drawbacks of the prior art listed above.

For this purpose, the device for supplying oxygen to occupants of an aircraft according to the invention, which also conforms to the generic definition thereof given in the above preamble, is essentially characterized in that the first and second expanding/regulating means are placed within one and the same regulator.

Furthermore, the invention may comprise one or more of the following features:

-   -   the device comprises means for cutting off the oxygen feed to         the first and/or the second oxygen supply line, such as a manual         valve, and in that the means for cutting off the feed are placed         within the regulator,     -   the second means for expanding/regulating the oxygen comprise an         electrically controlled mechanized regulating valve,     -   the electrically controlled mechanized regulating valve is         conformed for regulating a pressure and/or an oxygen flow into         the second line according to data representative of an altitude,     -   the device comprises at least one of the following sensors:         altitude sensor, a sensor for measuring the oxygen pressure at         the outlet of the source and upstream of the         expanding/regulating means, a temperature sensor, a sensor for         measuring the oxygen pressure downstream of the second         expanding/regulating means, and in that at least a part of the         sensor or sensors is placed within the regulator,     -   the first expanding/regulating means comprise a pneumatic         expansion valve,     -   the regulator is placed close to and is preferably connected         directly to the oxygen source,     -   the device comprises at least one quick installation mask         connected to the first oxygen supply line and at least one         passenger mask connected to the second oxygen supply line,     -   the regulator comprises a regulating line provided with an inlet         connected to the high pressure oxygen source (HP), the first and         second expanding means being placed in series on the regulating         line and upstream of a low pressure outlet connected to the         second oxygen supply line, and in that the regulating line         comprises a branch line connected between the first and second         expanding means and an outlet at the intermediate pressure, the         outlet at the intermediate pressure being connected to the first         oxygen supply line.

Other features and advantages will appear from a reading of the following description, with reference to the figures in which:

FIG. 1 shows a schematic view illustrating an exemplary embodiment of the oxygen supply device according to the invention,

FIG. 2 shows a detail of FIG. 1 schematically illustrating the structure and operation of a regulator according to the invention,

FIG. 3 schematically shows a mechanized pressure regulating valve.

FIG. 1 shows an oxygen gas source symbolized by a cylinder 1 (obviously, the invention can apply to a source comprising a plurality of cylinders or any other equivalent means). The source 1 contains oxygen gas at a high pressure, for example between 120 and 200 bar.

A regulator 6 described in greater detail below is connected to the outlet of the cylinder 1.

A first oxygen supply line 3 is connected to a first outlet 13 of the regulator 6. The first line 3 is used to feed oxygen to the first consumers, for example at least one quick installation mask 12. The first oxygen supply line 3 is provided for conveying oxygen to the masks 12 at an intermediate pressure IP delivered by the regulator 6 from the cylinder 1.

The circuit comprises a second oxygen supply line 5 connected to a second outlet 15 of the regulator 6.

The second line 5 is used to feed oxygen to the second consumer(s) 13, for example at least one passenger mask 13. The second oxygen supply line 5 is provided for conveying oxygen to the passenger masks 13 at a low pressure LP (for example between 0.5 and 5 bar gauge). The oxygen at the low pressure LP is delivered by the regulator 6 from the cylinder 1.

The regulator 6 comprises first 2 and second 4 expanding/regulating means for feeding the first line 3 with oxygen at the intermediate pressure IP and the second line 5 with oxygen at the low pressure LP.

Preferably and as described in greater detail below, the regulator 6 comprises electronic means. For this purpose, the regulator 6 is supplied by an electric power source 14. Furthermore, the regulator 6 may be associated with display and/or control means 16.

With reference to FIG. 2, the regulator 6 comprises an inlet 19 of a regulating line 20 to be fed with oxygen at high pressure HP issuing from the source 1. Downstream of the inlet 19, the regulating line 20 of the regulator 6 comprises first expanding means 2 preferably comprising a high pressure expansion valve provided for expanding the oxygen to an intermediate pressure IP. The high pressure expansion valve 2 is preferably a pneumatic expansion valve, but obviously, any other type of expander/regulator may be considered, such as an electronic regulator. Downstream of the high pressure expansion valve 2, the regulating line 20 of the regulator 6 comprises a valve 7, preferably manual, for cutting off the oxygen feed.

Downstream of the cutoff valve 7, the regulator 6 comprises an electrically controlled mechanized regulating valve 4 conformed for regulating the pressure and/or oxygen flow rate according to the altitude of the aircraft. Downstream of the mechanized regulating valve 4, the regulating line 20 comprises a low pressure LP outlet 15 for connection to the second oxygen supply line 5.

Between the cutoff valve 7 and the mechanized regulating valve 4, the regulating line 20 comprises a downstream branch line 120 to an outlet 13 at the intermediate pressure IP. This outlet 13 is intended to be connected to the first oxygen supply line 3 for feeding the first line 3 with oxygen at the intermediate pressure IP.

For controlling the mechanized regulating valve 4 in particular, the regulator 6 comprises control electronics 22 connected to an altimeter 8 and a sensor 11 measuring the oxygen pressure downstream of the mechanized regulating valve 4.

A temperature sensor 10 and a sensor 9 measuring the oxygen pressure upstream of the high pressure expansion valve 2 are also connected to the control electronics 22 for measuring the high pressure HP for temperature compensation of the pressure measurement, in order to determine the exact quantity of gas available.

The control electronics 22 may be connected to a connector of a diagnostic apparatus 23.

Upstream of the high pressure expansion valve 2, an upstream branch line 27 is provided to an inlet 24 (or high pressure oxygen filling connector) and a safety outlet 25 (for oxygen discharge). Between the inlet 24 and outlet 25, the upstream branch line 27 comprises a safety member 26 such as a disk which can break when subjected to a pressure limit to provide an opening to the discharge outlet 25. Downstream, the upstream branch line 27 joins the downstream branch line 20.

The regulator 6 is supplied by an electric power source 14 and may cooperate with a control module 29 delivering operating instructions I (“open”; “close”) corresponding respectively to:

-   -   Open=the regulator 6 is ready to operate in case of detection of         a decompression or is in operation (delivering oxygen downstream         into the circuit 5).     -   Closed=the regulator 6 is closed and isolates the gas         distribution to the circuit 5. Only the circuit 3 is supplied.

Finally, the regulator 6 may comprise or be associated with an output module 23 suitable for generating data such as:

-   -   no error in the operation of the device,     -   the device is active/inactive,     -   the manual valve is totally closed,     -   a selected closed position of the regulator 6,     -   the oxygen filling pressure,     -   warning due to an excessively low oxygen pressure.

The regulating valve 4 is suitable for sending a pressure peak to activate the passenger masks 13 (via an automatic opening of the mask cabinet) during the detection of a decompression in the cabin. Advantageously, the regulating valve 4 may be conformed to be tested for satisfactory operation.

Thus, while having a simple and inexpensive structure compared with the known systems, the device according to the invention allows an optimal oxygen supply at various pressures (IP, LP) to the emergency apparatus of an aircraft.

The integration of all the oxygen pressure regulating functions (intermediate IP and low LP) within one and the same regulator 6 serves to decrease or even to eliminate the intermediate pressure IP oxygen lines in certain apparatus. Furthermore, the device according to the invention allows a simplification of the emergency oxygen supply architecture and its maintenance. Moreover, the device according to the invention serves to integrate, in one and the same unit, the emergency oxygen pressure regulating functions necessary both for civilian aircraft and for business aircraft.

According to a feasible alternative, a safety bypass line (bypass) can be provided to short-circuit the valve 4 to feed the masks in case of failure of the valve 4. 

1-10. (canceled)
 11. A device for supplying oxygen to occupants of an aircraft, comprising an oxygen source at a first pressure known as a high pressure, a first oxygen supply line at a second pressure known as an intermediate pressure, first means for expanding/regulating the oxygen from the source to the second intermediate pressure, to feed the first oxygen supply line, a second oxygen supply line at a third pressure known as a low pressure, second means for expanding/regulating the oxygen from the source to the third pressure to feed the second oxygen supply line, wherein the first and second expanding/regulating means are placed within one and the same regulator.
 12. The device of claim 11, wherein the device further comprises means for cutting off the oxygen feed to the first and/or the second oxygen supply line, such as a manual valve, and in that the means for cutting off the feed are placed within the regulator.
 13. The device of claim 12, wherein the means for cutting off the oxygen feed is a manual valve.
 14. The device of claim 11, wherein the second means for expanding/regulating the oxygen comprise an electrically controlled mechanized regulating valve.
 15. The device of claim 14, wherein the electrically controlled mechanized regulating valve is conformed for regulating a pressure and/or an oxygen flow into the second line according to data representative of an altitude.
 16. The device of claim 14, wherein the device further comprises at least one of the following sensors: altitude sensor, a sensor for measuring the oxygen pressure at the outlet of the source and upstream of the expanding/regulating means, a temperature sensor, a sensor for measuring the oxygen pressure downstream of the second expanding/regulating means, and in that at least a part of the sensor or sensors is placed within the regulator.
 17. The device of claim 11, wherein the first expanding/regulating means comprise a pneumatic expansion valve.
 18. The device of claim 11, wherein the regulator is placed close to and is preferably connected directly to the oxygen source.
 19. The device of claim 18, wherein the regulator is connected directly to the oxygen source.
 20. The device of claim 11, wherein the device further comprises at least one quick installation mask connected to the first oxygen supply line and at least one passenger mask connected to the second oxygen supply line.
 21. The device of claim 11, wherein the regulator comprises a regulating line provided with an inlet connected to the high pressure (HP) oxygen source, the first and second expanding means being placed in series on the regulating line and upstream of a low pressure outlet connected to the second oxygen supply line, and in that the regulating line comprises a branch line connected between the first and second expanding means and an outlet at the intermediate pressure, the outlet at the intermediate pressure being connected to the first oxygen supply line.
 22. A pressure regulator for a device supplying oxygen to occupants of an aircraft comprising, integrated in one and the same module, first and second expanding/regulating means for expanding/regulating the oxygen issuing from the high pressure oxygen source, the first expanding/regulating means being conformed for expanding the oxygen to an intermediate pressure, the second expanding/regulating means comprising electrically controlled mechanized means for regulating the pressure and/or flow rate of oxygen to a pressure known as a low pressure according to data representative of an altitude. 